
//===------------------------- ItaniumDemangle.cpp ------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// FIXME: (possibly) incomplete list of features that clang mangles that this
// file does not yet support:
//   - C++ modules TS

#include "include/Demangle.h"
#include "include/Utility.h"
#include "include/ItaniumDemangle.h"

#include <cassert>
#include <cctype>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <numeric>
#include <utility>
#include <vector>

using namespace llvm;
using namespace llvm::itanium_demangle;

constexpr const char *itanium_demangle::FloatData<float>::spec;
constexpr const char *itanium_demangle::FloatData<double>::spec;
constexpr const char *itanium_demangle::FloatData<long double>::spec;

// <discriminator> := _ <non-negative number>      # when number < 10
//                 := __ <non-negative number> _   # when number >= 10
//  extension      := decimal-digit+               # at the end of string
const char *itanium_demangle::parse_discriminator(const char *first, const char *last) {
  // parse but ignore discriminator
  if (first != last) {
    if (*first == '_') {
      const char *t1 = first + 1;
      if (t1 != last) {
        if (std::isdigit(*t1))
          first = t1 + 1;
        else if (*t1 == '_') {
          for (++t1; t1 != last && std::isdigit(*t1); ++t1)
            ;
          if (t1 != last && *t1 == '_') first = t1 + 1;
        }
      }
    } else if (std::isdigit(*first)) {
      const char *t1 = first + 1;
      for (; t1 != last && std::isdigit(*t1); ++t1)
        ;
      if (t1 == last) first = last;
    }
  }
  return first;
}

#ifndef NDEBUG
namespace {
struct DumpVisitor {
  unsigned Depth      = 0;
  bool PendingNewline = false;

  template <typename NodeT> static constexpr bool wantsNewline(const NodeT *) { return true; }
  static bool wantsNewline(NodeArray A) { return !A.empty(); }
  static constexpr bool wantsNewline(...) { return false; }

  template <typename... Ts> static bool anyWantNewline(Ts... Vs) {
    for (bool B : {wantsNewline(Vs)...})
      if (B) return true;
    return false;
  }

  void printStr(const char *S) { fprintf(stderr, "%s", S); }
  void print(StringView SV) { fprintf(stderr, "\"%.*s\"", (int) SV.size(), SV.begin()); }
  void print(const Node *N) {
    if (N)
      N->visit(std::ref(*this));
    else
      printStr("<null>");
  }
  void print(NodeArray A) {
    ++Depth;
    printStr("{");
    bool First = true;
    for (const Node *N : A) {
      if (First)
        print(N);
      else
        printWithComma(N);
      First = false;
    }
    printStr("}");
    --Depth;
  }

  // Overload used when T is exactly 'bool', not merely convertible to 'bool'.
  void print(bool B) { printStr(B ? "true" : "false"); }

  template <class T> std::enable_if_t<std::is_unsigned<T>::value> print(T N) {
    fprintf(stderr, "%llu", (unsigned long long) N);
  }

  template <class T> std::enable_if_t<std::is_signed<T>::value> print(T N) { fprintf(stderr, "%lld", (long long) N); }

  void print(ReferenceKind RK) {
    switch (RK) {
    case ReferenceKind::LValue: return printStr("ReferenceKind::LValue");
    case ReferenceKind::RValue: return printStr("ReferenceKind::RValue");
    }
  }
  void print(FunctionRefQual RQ) {
    switch (RQ) {
    case FunctionRefQual::FrefQualNone: return printStr("FunctionRefQual::FrefQualNone");
    case FunctionRefQual::FrefQualLValue: return printStr("FunctionRefQual::FrefQualLValue");
    case FunctionRefQual::FrefQualRValue: return printStr("FunctionRefQual::FrefQualRValue");
    }
  }
  void print(Qualifiers Qs) {
    if (!Qs) return printStr("QualNone");
    struct QualName {
      Qualifiers Q;
      const char *Name;
    } Names[] = {
        {QualConst, "QualConst"},
        {QualVolatile, "QualVolatile"},
        {QualRestrict, "QualRestrict"},
    };
    for (QualName Name : Names) {
      if (Qs & Name.Q) {
        printStr(Name.Name);
        Qs = Qualifiers(Qs & ~Name.Q);
        if (Qs) printStr(" | ");
      }
    }
  }
  void print(SpecialSubKind SSK) {
    switch (SSK) {
    case SpecialSubKind::allocator: return printStr("SpecialSubKind::allocator");
    case SpecialSubKind::basic_string: return printStr("SpecialSubKind::basic_string");
    case SpecialSubKind::string: return printStr("SpecialSubKind::string");
    case SpecialSubKind::istream: return printStr("SpecialSubKind::istream");
    case SpecialSubKind::ostream: return printStr("SpecialSubKind::ostream");
    case SpecialSubKind::iostream: return printStr("SpecialSubKind::iostream");
    }
  }
  void print(TemplateParamKind TPK) {
    switch (TPK) {
    case TemplateParamKind::Type: return printStr("TemplateParamKind::Type");
    case TemplateParamKind::NonType: return printStr("TemplateParamKind::NonType");
    case TemplateParamKind::Template: return printStr("TemplateParamKind::Template");
    }
  }
  void print(SpecialNameType SNT) {
    switch (SNT) {
    case SpecialNameType::virtual_table: printStr("virtual_table"); break;
    case SpecialNameType::virtual_table_table: printStr("virtual_table_table"); break;
    case SpecialNameType::type_info: printStr("type_info"); break;
    case SpecialNameType::type_info_name: printStr("type_info_name"); break;
    case SpecialNameType::covariant_return_thunk: printStr("covariant_return_thunk"); break;
    case SpecialNameType::construction_virtual_table: printStr("construction_virtual_table"); break;
    case SpecialNameType::thread_local_wrapper: printStr("thread_local_wrapper"); break;
    case SpecialNameType::thread_local_initialization: printStr("thread_local_initialization"); break;
    case SpecialNameType::virtual_thunk: printStr("virtual_thunk"); break;
    case SpecialNameType::non_virtual_thunk: printStr("non_virtual_thunk"); break;
    case SpecialNameType::guard_variable: printStr("guard_variable"); break;
    case SpecialNameType::reference_temporary: printStr("reference_temporary"); break;
    case SpecialNameType::invocation_function_block: printStr("invocation_function_block"); break;
    default: break;
    }
  }

  void newLine() {
    printStr("\n");
    for (unsigned I = 0; I != Depth; ++I) printStr(" ");
    PendingNewline = false;
  }

  template <typename T> void printWithPendingNewline(T V) {
    print(V);
    if (wantsNewline(V)) PendingNewline = true;
  }

  template <typename T> void printWithComma(T V) {
    if (PendingNewline || wantsNewline(V)) {
      printStr(",");
      newLine();
    } else {
      printStr(", ");
    }

    printWithPendingNewline(V);
  }

  struct CtorArgPrinter {
    DumpVisitor &Visitor;

    template <typename T, typename... Rest> void operator()(T V, Rest... Vs) {
      if (Visitor.anyWantNewline(V, Vs...)) Visitor.newLine();
      Visitor.printWithPendingNewline(V);
      int PrintInOrder[] = {(Visitor.printWithComma(Vs), 0)..., 0};
      (void) PrintInOrder;
    }
  };

  template <typename NodeT> void operator()(const NodeT *Node) {
    Depth += 2;
    fprintf(stderr, "%s(", itanium_demangle::NodeKind<NodeT>::name());
    Node->match(CtorArgPrinter{*this});
    fprintf(stderr, ")");
    Depth -= 2;
  }

  void operator()(const ForwardTemplateReference *Node) {
    Depth += 2;
    fprintf(stderr, "ForwardTemplateReference(");
    if (Node->Ref && !Node->Printing) {
      Node->Printing = true;
      CtorArgPrinter{*this}(Node->Ref);
      Node->Printing = false;
    } else {
      CtorArgPrinter{*this}(Node->Index);
    }
    fprintf(stderr, ")");
    Depth -= 2;
  }
};
} // namespace

void itanium_demangle::Node::dump() const {
  DumpVisitor V;
  visit(std::ref(V));
  V.newLine();
}
#endif

//===----------------------------------------------------------------------===//
// Code beyond this point should not be synchronized with libc++abi.
//===----------------------------------------------------------------------===//

struct Demangler : itanium_demangle::ManglingParser<DefaultAllocator> {
  using ManglingParser::ManglingParser;
};

char *llvm::itaniumDemangle(const char *MangledName, char *Buf, size_t *N, int *Status) {
  if (MangledName == nullptr || (Buf != nullptr && N == nullptr)) {
    if (Status) *Status = demangle_invalid_args;
    return nullptr;
  }

  int InternalStatus = demangle_success;
  Demangler Parser(MangledName, MangledName + std::strlen(MangledName));
  OutputStream S;

  Node *AST = Parser.parse();

  if (AST == nullptr)
    InternalStatus = demangle_invalid_mangled_name;
  else if (!initializeOutputStream(Buf, N, S, 1024))
    InternalStatus = demangle_memory_alloc_failure;
  else {
    assert(Parser.ForwardTemplateRefs.empty());
    AST->print(S);
    S += '\0';
    if (N != nullptr) *N = S.getCurrentPosition();
    Buf = S.getBuffer();
  }

  if (Status) *Status = InternalStatus;
  return InternalStatus == demangle_success ? Buf : nullptr;
}

ItaniumPartialDemangler::ItaniumPartialDemangler() : RootNode(nullptr), Context(new Demangler{nullptr, nullptr}) {}

ItaniumPartialDemangler::~ItaniumPartialDemangler() { delete static_cast<Demangler *>(Context); }

ItaniumPartialDemangler::ItaniumPartialDemangler(ItaniumPartialDemangler &&Other)
    : RootNode(Other.RootNode), Context(Other.Context) {
  Other.Context = Other.RootNode = nullptr;
}

ItaniumPartialDemangler &ItaniumPartialDemangler::operator=(ItaniumPartialDemangler &&Other) {
  std::swap(RootNode, Other.RootNode);
  std::swap(Context, Other.Context);
  return *this;
}

// Demangle MangledName into an AST, storing it into this->RootNode.
bool ItaniumPartialDemangler::partialDemangle(const char *MangledName) {
  Demangler *Parser = static_cast<Demangler *>(Context);
  size_t Len        = std::strlen(MangledName);
  Parser->reset(MangledName, MangledName + Len);
  RootNode = Parser->parse();
  return RootNode == nullptr;
}

static char *printNode(const Node *RootNode, char *Buf, size_t *N) {
  OutputStream S;
  if (!initializeOutputStream(Buf, N, S, 128)) return nullptr;
  RootNode->print(S);
  S += '\0';
  if (N != nullptr) *N = S.getCurrentPosition();
  return S.getBuffer();
}

char *ItaniumPartialDemangler::getFunctionBaseName(char *Buf, size_t *N) const {
  if (!isFunction()) return nullptr;

  const Node *Name = static_cast<const FunctionEncoding *>(RootNode)->getName();

  while (true) {
    switch (Name->getKind()) {
    case Node::KAbiTagAttr: Name = static_cast<const AbiTagAttr *>(Name)->Base; continue;
    case Node::KStdQualifiedName: Name = static_cast<const StdQualifiedName *>(Name)->Child; continue;
    case Node::KNestedName: Name = static_cast<const NestedName *>(Name)->Name; continue;
    case Node::KLocalName: Name = static_cast<const LocalName *>(Name)->Entity; continue;
    case Node::KNameWithTemplateArgs: Name = static_cast<const NameWithTemplateArgs *>(Name)->Name; continue;
    default: return printNode(Name, Buf, N);
    }
  }
}

char *ItaniumPartialDemangler::getFunctionDeclContextName(char *Buf, size_t *N) const {
  if (!isFunction()) return nullptr;
  const Node *Name = static_cast<const FunctionEncoding *>(RootNode)->getName();

  OutputStream S;
  if (!initializeOutputStream(Buf, N, S, 128)) return nullptr;

KeepGoingLocalFunction:
  while (true) {
    if (Name->getKind() == Node::KAbiTagAttr) {
      Name = static_cast<const AbiTagAttr *>(Name)->Base;
      continue;
    }
    if (Name->getKind() == Node::KNameWithTemplateArgs) {
      Name = static_cast<const NameWithTemplateArgs *>(Name)->Name;
      continue;
    }
    break;
  }

  switch (Name->getKind()) {
  case Node::KStdQualifiedName: S += "std"; break;
  case Node::KNestedName: static_cast<const NestedName *>(Name)->Qual->print(S); break;
  case Node::KLocalName: {
    auto *LN = static_cast<const LocalName *>(Name);
    LN->Encoding->print(S);
    S += "::";
    Name = LN->Entity;
    goto KeepGoingLocalFunction;
  }
  default: break;
  }
  S += '\0';
  if (N != nullptr) *N = S.getCurrentPosition();
  return S.getBuffer();
}

char *ItaniumPartialDemangler::getFunctionName(char *Buf, size_t *N) const {
  if (!isFunction()) return nullptr;
  auto *Name = static_cast<FunctionEncoding *>(RootNode)->getName();
  return printNode(Name, Buf, N);
}

char *ItaniumPartialDemangler::getFunctionParameters(char *Buf, size_t *N) const {
  if (!isFunction()) return nullptr;
  NodeArray Params = static_cast<FunctionEncoding *>(RootNode)->getParams();

  OutputStream S;
  if (!initializeOutputStream(Buf, N, S, 128)) return nullptr;

  S += '(';
  Params.printWithComma(S);
  S += ')';
  S += '\0';
  if (N != nullptr) *N = S.getCurrentPosition();
  return S.getBuffer();
}

char *ItaniumPartialDemangler::getFunctionReturnType(char *Buf, size_t *N) const {
  if (!isFunction()) return nullptr;

  OutputStream S;
  if (!initializeOutputStream(Buf, N, S, 128)) return nullptr;

  if (const Node *Ret = static_cast<const FunctionEncoding *>(RootNode)->getReturnType()) Ret->print(S);

  S += '\0';
  if (N != nullptr) *N = S.getCurrentPosition();
  return S.getBuffer();
}

char *ItaniumPartialDemangler::finishDemangle(char *Buf, size_t *N) const {
  assert(RootNode != nullptr && "must call partialDemangle()");
  return printNode(static_cast<Node *>(RootNode), Buf, N);
}

bool ItaniumPartialDemangler::hasFunctionQualifiers() const {
  assert(RootNode != nullptr && "must call partialDemangle()");
  if (!isFunction()) return false;
  auto *E = static_cast<const FunctionEncoding *>(RootNode);
  return E->getCVQuals() != QualNone || E->getRefQual() != FrefQualNone;
}

bool ItaniumPartialDemangler::isCtorOrDtor() const {
  const Node *N = static_cast<const Node *>(RootNode);
  while (N) {
    switch (N->getKind()) {
    default: return false;
    case Node::KCtorDtorName: return true;

    case Node::KAbiTagAttr: N = static_cast<const AbiTagAttr *>(N)->Base; break;
    case Node::KFunctionEncoding: N = static_cast<const FunctionEncoding *>(N)->getName(); break;
    case Node::KLocalName: N = static_cast<const LocalName *>(N)->Entity; break;
    case Node::KNameWithTemplateArgs: N = static_cast<const NameWithTemplateArgs *>(N)->Name; break;
    case Node::KNestedName: N = static_cast<const NestedName *>(N)->Name; break;
    case Node::KStdQualifiedName: N = static_cast<const StdQualifiedName *>(N)->Child; break;
    }
  }
  return false;
}

bool ItaniumPartialDemangler::isFunction() const {
  assert(RootNode != nullptr && "must call partialDemangle()");
  return static_cast<const Node *>(RootNode)->getKind() == Node::KFunctionEncoding;
}

bool ItaniumPartialDemangler::isSpecialName() const {
  assert(RootNode != nullptr && "must call partialDemangle()");
  auto K = static_cast<const Node *>(RootNode)->getKind();
  return K == Node::KSpecialName || K == Node::KCtorVtableSpecialName;
}

bool ItaniumPartialDemangler::isData() const { return !isFunction() && !isSpecialName(); }
